Somjai Kowsurat และ Prayahd Pholloke; Sripoom Kong-in; Sorasak Maneekao; Tamrong Chuekittisak. (2006) Ubonratchathani Black Grain Cowpea. <i>Thai Agricultural Research Journal</i>, <i>24</i>(1), 52-66.Somjai Kowsurat และ Prayahd Pholloke; Sripoom Kong-in; Sorasak Maneekao; Tamrong Chuekittisak. "Ubonratchathani Black Grain Cowpea". Thai Agricultural Research Journal 24 (2006):52-66.Somjai Kowsurat และ Prayahd Pholloke; Sripoom Kong-in; Sorasak Maneekao; Tamrong Chuekittisak. Ubonratchathani Black Grain Cowpea. Department of Agriculture:ม.ป.ท. 2006.